An Iraqi Kurdish soldier stands in Halabja cemetery in northern Iraq on March 16, 2005. Over 5,000 of the town's residents were killed in a chemical weapons attack by Saddam Hussein's regime in March of 1988. (Namir Noor-Eldeen/Reuters)

After a brief scare last week, the Obama administration now believes
that the threat of Syrian dictator Bashar al-Assad using his sizable stock of
chemical weapons has
abated. But that doesn't mean the threat is entirely gone: as the rebels
advance, and as strategic flashpoints like the Damascus airport threaten to fall
out of the regime's direct control, the temptation to clear neighborhoods and intimidate Assad's opponents could become overwhelming.

For the Obama administration, the use of chemical weapons in
Syria would transform official U.S. understanding of the conflict. War with chemical weapons would be of an entirely different order than the current fighting, said Robert Ford, the former U.S. ambassador to Syria who appeared with
regime opponents in the besieged city of Homs before he was recalled from the
country in February, in an appearance at the Foundation for Defense of Democracies' last week.

"Utilization of these
weapons in any way crosses a U.S. red line," he said during his prepared
remarks. In a reply to an audience question, Ford said that possible consequences
for crossing this line were "above my pay grade." But he added that "the use of
these weapons is for us a qualitatively different situation ... it will change our
calculus in a fundamental way."

It makes sense for Ford to avoid elaborating on possible
U.S. action in response to the use of chemical weapons in Syria -- all it takes
is one careless statement to give off the appearance that the Obama administration
has implicitly committed itself to some form of military intervention. If the administration were to attempt an attack on Assad's chemical weapons capability, such an intervention likely would not be a minor one. Bombing Assad's
chemical facilities from the air would disperse deadly sarin gas; depending on
which way the wind were blowing, it could be carried into civilian areas or even
neighboring countries. The Department
of Defense estimates it could take up to 75,000 troops to secure Syria's
chemical weapons stock. And then the weapons would have to be disposed of.
According to Paul Walker of Global Green
U.S.A., it will take another 10 years and $10 billion to destroy the 2,800
metric tons of chemical weapons remaining in the U.S's arsenal. Securing and
disposing of Assad's 500
metric tons of ordinance will be costly, labor-intensive, and
time-consuming.

"The use of
these weapons is for us a qualitatively different situation...it will change our
calculus in a fundamental way."

The administration seems convinced that the use of chemical
weapons would make the conflict something more than simply an internal matter.
As Dominic Tierney has noted at The Atlantic, this type of thinking creates
something of a double-standard. "Oddly, the international community seems less
concerned by how many people the Syrian regime kills than by the methods
it uses to kill them," wrote
Tierney. "The rule of murdering your population is: Don't use chemical weapons."

Simon Adams, executive director of the Global Centre for the Responsibility to
Protect, echoed Tierney when I spoke with him last week. "This regime has
already violated every international human rights and humanitarian law, and has
essentially gotten away with it," he said. Adams emphasized that the use of
chemical weapons doesn't necessarily change the conflict from a humanitarian point
of view. "From a responsibility-to-protect perspective, this is already a regime
that is beyond the pale and which has broken international law and which needs
to be held accountable."

The Obama administration's belief in the difference between war by conventional- and unconventional weapons must be grounded in something other than
the immediate threat to human life -- something more universal, and more
abstract, than the prospect of more dead Syrians. But what?

I contacted Paul Walker to get an answer to that question. Walker
is a leading expert on chemical weapons
disarmament, and he explained what makes this category of weaponry so
uniquely horrible.

"Any weapon may be inhumane and indiscriminate to some
extent, but chemical weapons are designed to be inhuman and indiscriminate,"
says Walker. Sarin is particularly deadly. "The inhalation or ingestion of any minuscule
amount will kill you in about four minutes," he explained. "It basically breaks
down the whole nervous system. You lose control of any of your bodily functions.
You eventually aren't able to stand or move your arms. You're only able to breathe
or have your heart beat." Sarin can carry 50 miles or more. It gets in the ground
water, and over time it can revert to a toxic precursor state if the environmental
conditions are right. "It's really dense," he says. "It's the deadliest stuff
on earth."

The unpredictability of chemical weapons makes them tactically useless. A commander could hit a large group of enemy soldiers
with sarin gas -- but he'd likely kill his own troops, turn the battlefield into an inaccessible wasteland, or kill civilians. The fact that nobody dared use them was what made a chemical weapons ban possible in the first place --
first under the 1925
Geneva Protocol on Gas Warfare, and then under the 1993 Chemical Weapons Convention,
which all but eight countries have ratified (Angola, Myanmar, North Korea, Israel,
Syria, Egypt, Somalia and South Sudan. Israel and Myanmar have signed the Convention
without ratifying it).

Some administration officials have grappled before with the ethics of chemical warfare, and its place in a different strategic and moral universe than
conventional conflict. In the
acclaimed A Problem from Hell, Obama adviser Samantha Power
explains how American perceptions of Saddam Hussein's campaign against Kurdish civilians in northern Iraq changed as
soon as his use of chemical weapons could be definitively proven.

In 1987, then-Senate Committee on Foreign Relations staffer
Peter W. Galbraith was pushing for sanctions against Saddam's regime. At the time, the U.S. was
still supporting the dictator in his war against neighboring Iran. But, as Power writes:

Galbraith had something unseemly working in his favor. Since
April 1987 Hussein had been purging and killing Kurds with a variety of
weapons. But this most recent offensive involved chemical weapons, which killed
in a more grisly way than machine guns and captured the imagination of U.S.
lawmakers. Ensconced in a country attacked only once in the 20th century,
most Americans did not feel vulnerable when foreign slaughter was discussed.
Before September 11, 2001, most Americans believed that the large-scale murder
of civilians could only occur miles from home. But chemical weapons were different.
They had crept into American consciousness because they did not respect
national rankings and were unimpressed by geographic isolation. No matter how
thick U.S. defenses, the gasses could penetrate. ...

U.S. senators knew that chemical weapons had become all too
easy to acquire in the 1980s. Nuclear weapons required either plutonium or
highly enriched uranium, which had few suppliers, and sophisticated chemical
and engineering processes and equipment were needed to convert the fissionable
material. Chemical weapons, by contrast, were cheap and said to take a garage
and a little high school chemistry to make. They were the poor man's nuke.

The "Prevention of Genocide Act" unanimously passed the Senate
following reports of Saddam's chemical weapons use. "It looked to
[Galbraith] and most observers as if, to paraphrase Holocaust survivor Primo Levi,
it was the good fortune of Iraqi Kurds to be attacked with chemical weapons,"
Power wrote.

Chemical weapons are almost universally understood to be an expedient
for effecting massive amounts of human suffering, and nothing more. Reinforcing the international norm against them can be thought of as an end in itself, and it may help explain the Obama administration's stance on Syria.

Still, any norm that focuses on the tools of destruction -- rather than the political evils served by mass killings -- misses the point. Galbraith seemed to sense this. "'Most
of those senators were concerned not with the Kurds but with the instrument of
death, the chemical weapons,'" Galbraith tells Power. "'I wasn't concerned with
the use of chemical weapons as such but with their use as a way of destroying
the Kurdish people. These weapons were not any more evil than guns.'"